Syrian state media say at least five people were killed and 20 others wounded in a car-bomb attack an army checkpoint on the southern outskirts of the capital, Damascus.

SANA news agency said a suicide attacker blew up his vehicle on April 25 after he was discovered by one of the soldiers manning the checkpoint in the district of Sayeda Zeinab, a government stronghold.

The Britain-based Syrian Observatory for Human Rights gave a higher death toll, saying at least eight people were killed in the attack.

The Islamic State (IS) extremist group claimed responsibility for the bombing in Sayeda Zeinab, a home to an important Shi'ite shrine.

Bomb attacks on checkpoints in Sayeda Zeinab in January and February killed nearly 200 people, according to the Observatory. Those attacks were also claimed by IS militants.